The term environment relates both to a closed area, such as a room or a hall, and to open spaces not necessarily enclosed by walls. Among the possible applications, the device could in fact be used:                in the industry of medical devices production, in which “sterile chambers”, where medical devices for human and veterinary use are produced, need to be controlled;        in the agri-food industry, in which an environmental control must be effected and the processing of food products subject to microbiological degradation is carried out;        in hospitals, where operating and hospital rooms at high microbiological risk need to be controlled;        in the electronics industry, in which an environmental control must be effected and microelectronic and aerospace components are produced for the microbiological monitoring of the cabins and shuttles that go into the space.        
When the characteristics of a certain environment or sample must be assessed with respect to its content of microorganisms, both devices capable of putting in contact the microorganisms contained in said environmental, and an element for entrapping said microorganisms are used. A type of widely used entrapping element consists of round boxes containing sterile gelatinous mediums, normally based on agar.
Known portable sampling devices currently comprise a main body equipped with a handle that bears, at one of its ends, a support wherein the box containing the gelatinous medium is inserted. The support has an annular structure and the box with the gelatinous medium is placed at a through-hole connected to a suction group. On the box with the gelatinous medium there is a cover equipped with numerous small calibrated holes through which air is sucked.
The traditional devices are also provided with an electronic control unit that controls the switching on and the switching off of the suction unit and implements the timer function. When the device is used for sampling the air contained in a certain environment or volume, the control unit activates the suction group that draws the air, making it pass through the cover with the calibrated holes.
The air comes into contact with the gelatinous medium and deposits onto the same the microorganisms present therein. The gelatinous medium is then analyzed in a known manner and the content of microorganisms in the air is identified.
Portable sampling devices of the known type are described, for example, in documents WO 03/081212 A2, U.S. Pat. No. 5,500,369 A, U.S. Pat. No. 6,565,638 B1 and US 2009/0268201 A1.
The traditional devices of the type indicated above can, in some cases, prove to be not very efficient and may not be indicative of the real content of microorganisms present in the environment or in the area to be analyzed. The air sampling is in fact effected at a narrow range of action and not, as it would be instead desirable, in several positions of the environment to be controlled, subsequently taking an average of the results obtained. In practice, therefore, the sample collected may not be indicative of the actual concentration of microorganisms in the whole environment due to a possible non-uniformity of concentration thereof. Although the problem can be overcome by taking several samplings in the same environment at different times and in different positions, however, also in this manner samples not very significant could be taken since, for example, the microorganisms could move.
Therefore, for sampling a certain environment, device of the known type is currently used so as to effect sequential samplings in different positions. These sequential samplings are effected by fixing the device on a support and programming the control unit so that this activates the suction group at prefixed time intervals. In practice, therefore, the device is switched on and subsequently switched off, controlled by the control unit, at predetermined time intervals between which the device is moved.
Also in this case, however, the samples taken may not be indicative of the actual content of microorganisms since, for example, particular conditions can generate in the environment, such as vortices or pressure and/or temperature gradients, which cause a recirculation of the air around the unique support for the gelatinous medium. Furthermore, since the microorganisms are usually carried by dust particles, even if the device were provided with a particularly efficient suction group, it would never be possible co capture all of the dust and the smallest particles could not be captured by the gelatinous medium. Hence, also in this case, the samples prove to be not particularly indicative of the real content of microorganisms in the environment.
In addition to errors of statistical nature, which per se have a very high incidence in microbiology, the known devices also have the problem that, by increasing the number of “resetting” operations, the device may be more frequently microbiologically contaminated by the manipulation of the operator.